Issue: May 6th

Is it too late to plant roses in New Mexico?

Is it too late to plant roses now?

In all of New Mexico it is too late to plant bare root roses (those that come in the pack with sawdust around the roots). However, containerized roses (those in pots in the nursery) can be planted. They may suffer some transplant shock, so be careful to keep them moist and protected from full sunlight and wind for a while after you plant them. You can do this by protecting them inside a tomato cage wrapped with white floating row cover material or any porous white material that will diffuse light and block the wind. As the plant establishes and grows too large for the tomato cage, you can remove the covering.

Check the potting soil in which the roses are growing. If it is mostly bark, you may need to wash it off and quickly plant it in a rose bed well amended with compost. If it is in a clay soil and you are planting in sandy soil, amend the sandy soil with organic matter and loosen the soil around the root ball. In any case, add a considerable amount of well-composted organic matter to the planting bed. It would also be wise to add a phosphate fertilizer, super phosphate or colloidal phosphate. The phosphorus will be necessary in the formation of the flowers. Don't over-apply phosphorus as that can cause problems, but the addition of some phosphorus is helpful.

Damaged rose blossoms

Why are my rose blossoms ugly? The petals are brown and distorted.

There are several potential answers to your question. One is that the flowers are infested with thrips. Thrips are very small insects that are a problem with roses, especially in their first blooming of the year. If you carefully check inside the flower, pulling the petals open, you will often see a small speck scurrying away. This is the thrips insect. (Yes, there is an "s" on the end of its name even when we are speaking of a single thrips.) There are insecticides labeled for controlling thrips on roses. Call your local Cooperative Extension Service office for information, or check at your local garden center for a product that will work for you. Be sure to read the label and follow the directions for any product you wish to use.

Another cause of damage, often appearing in conjunction with the thrips, is desiccation caused by our intense sun, wind, and heat. Be sure the plants are not getting too dry and, if possible, provide some protection from wind and afternoon sunlight. You can plant a windbreak of tall-growing flowers, sunflowers and the like, or plant vines on a trellis on the windward side of your roses. In New Mexico that will often be on the southwest side where it will also provide some afternoon shade. Just be sure the roses get at least four-to-six hours of sunlight each day.

Marisa Y. Thompson, PhD, is the Extension Horticulture Specialist, in the Department of Extension Plant Sciences at the New Mexico State University Los Lunas Agricultural Science Center, email: desertblooms@nmsu.edu, office: 505-865-7340, ext. 113.

For more gardening information, visit the NMSU Extension Horticulture page at Desert Blooms and the NMSU Horticulture Publications page.

Send gardening questions to Southwest Yard and Garden - Attn: Dr. Marisa Thompson at desertblooms@nmsu.edu, or at the Desert Blooms Facebook.

Please copy your County Extension Agent and indicate your county of residence when you submit your question!